Yellow sulfur dye and process of making same.



Patented October 25, 1904.

UNITED STATES PATENT Orricn.

ALBRECHT SCHMIDT AND OTTO RHODIUS, OF HOOHST-ON THE-MAIN,

GERMANY, ASSIQNORS TO FARBVVERKE, VORM. MEISTER, LUOIUS & BR'UNING, OF HOOHST-ON-THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

YELLOW SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION formingpart of Letters Patent No. 773,346, dated October 25, 1904. Application filed June 23, 1904. Serial No- 213,759. (No specimens.)

To all whmn it may concern:

Be it known that we, ALBRECHT SCHMIDT. Ph. D., and OTTO RHODIUS, Ph. D., chemists, citizens of the Empire of Germany, residing at Hiichst-on-the-Main, Germany, have invented certain new and useful Improvements in the Manufacture of Yellow Sulfurized Dyestufls', of which the following is a specification.

WVe have found that yellow dyestuffs of great purity and fastness may be obtained if the products of reaction of carbon bisulfid on Inetatoluylenediamin are heated with sulfur at, for instance, 190 to 220 centigrade in presence of aromatic amins, such as benzidin or similarly-acting bases, and the products thus obtained are dissolved in alkali sulfids.

Example: Into one hundred and eighty parts, by weight,ofmelted sulfur is introduced at about 110 to 130 centigrade a mixture of thirty parts, by weight, of benzidin and the product of reaction of one molecular proportion of carbon bisulfid on one molecular proportion of metatoluylenediamin. The Whole is then heated for some hours to about 190 to 220 centigrade until a test portion treated with sodium sulfid has the desired shade and fast-ness. The sulfurized product thus obtainedis a brown powder insoluble in Water, alcohol, ether, and benzene, soluble in hot alkali sulfids. One hundred parts, by weight, of this product are introduced into two hundred and twentyfive parts, by weight, of melted sodium sulfid. The temperature is gradually raised While stirring, and the mass is dried, preferably, in a vacuum.

The product dyes cotton a beautiful pure yellow of great fastness. It is readily soluble in water and alcohol, and the free acid of the dyestuif is easily obtained by means of the usual precipitants. By modifying the temperature and time when sulfurizing the shade assumes a more or less red tint.

Having now described our invention, what We claim is- 1. The herein described process for the manufacture of yellow dyestuffs of great purity, which consists in heating at a high temperature the products of reaction of carbon bisulfid 0n metatoluylenediamin in presence of aromatic bases and in fusing the sulfurized products thus obtained With alkali sulfids.

2. As a new product, the pureyellow dyestuff obtained by heating the products of reaction of carbon bisulfid on metatoluylenediamin with sulfur in presence of aromatic amins, being a brown powder, insoluble in water, alcohol, ether and benzene, soluble in hot alkali sulfids.

In testimony that we claim the foregoing as our invention we have signed our names in presence of two subscribing witnesses.

ALBRECHT SCHMIDT. OTTO BHODIUS.

Witn esses ALFRED BmsBoIs, BERNHARD LEYDECKER. 

